The Application of Photogrammetric and Topographic Techniques to Investigate Submerged Caves: A Case Study of Georeferenced Point Installation at the Font of Ses Aiguades Cave (Alcúdia, Mallorca)

Abstract

In recent decades geoarchaeological techniques have increasingly been used to document archaeological remains in terrestrial and underwater sites. However, the archaeological record in submerged caves lacks systematic documentation techniques, due to difficulties of the environment and time limitations. These methodological constraints may result in incomplete documentation of an archaeological site and its artifacts. In the present work, we aim to combine geoarchaeological techniques, photogrammetry, topography, and manual surveying to geolocate archaeological remains dated to the Roman period of Mallorca (30 BCE [Before Common Era] and 70 Common Era (CE), in one of the most important submerged sites in Europe, the Font of Ses Aiguades cave in Alcúdia (Mallorca). An innovative methodological protocol based on non-intrusive surveying was applied to improve the historical, topographical, and archaeological knowledge of the cave. Here we propose a fast, rigorous, and economic documentation protocol for the generation of a georeferenced database of submerged archaeological remains. We also demonstrate the superior cost/benefit balance of generating a georeferenced photogrammetric three-dimensional model of a site versus manually calculating the geopositions of underwater archaeological artifacts. This study also corroborates the efficacy and accuracy of photogrammetry versus manual measurement.